Sump or GFO Reactor

Hey guy, my 36 gallon bowfront has been established for 3 years now. All parameters are good and it mostly has softies with a couple lps mixed in. Not overstocked as I only have four fish, and a few snails, hermits, and conch. I've noticed lately my glass, and pumps/powerheads get a thin layer of brown algae on them every 2-3 days. My phosphates are always below .2 and it doesn't grow on my rocks to the visible eye. I've been debating adding a sump or putting in a hob gfo reactor but can't decide which would benefit the tank more. There is plenty of water movement as I have three powerheads and a protien skimmer and all my coral look great. I'm leaning toward the sump as I can always add a reactor to it down the line. My issue is I will be moving in a year and don't want to plumb everything until I'm situation in my permanent home. Do you guys think it would be beneficial to install the reactor for the time being until I can add a sump?